The present invention relates to pull-on disposable wearing articles for absorption and containment of bodily discharges. The present application is based on, and claims priority from, Japanese Application Serial Number 2003-38977, filed Jan. 10, 2003, the disclosure of which is hereby incorporated by reference herein in its entirety.
Pull-on disposable wearing articles having front and rear waist regions opposed to each other, a crotch region extending between these waist regions, a waist-hole and a pair of leg-holes are well known, one of which is disclosed in Japanese Patent Application Publication No. 2002-35033A. This article comprises a liquid-pervious sheet, a liquid-impervious sheet and a liquid-absorbent core interposed between these sheets and extending over the crotch region and further into the front and rear waist regions. The crotch region is formed with tucks which are convex inwardly of the respective leg-holes.
The above-cited article has a waist-surrounding upper end margin defined by the front and rear waist regions and extending in a transverse direction, waists' lateral margins defined also by the front and rear waist regions and extending in a longitudinal direction and a pair of leg-surrounding lateral margins defined by the crotch region and extending in a leg-surrounding direction. The waists' lateral margins put flat together are joined one to another by means of plural welding lines arranged intermittently in the longitudinal direction. This article is formed with a pair of folding guide lines extending between the transversely opposite leg-surrounding lateral margins and intersecting at a transversely middle point in the crotch region. Thus the crotch region is divided into first and second zones enclosed by the leg-surrounding lateral margins and these folding guide lines, respectively, and a third zone except the first and second zones. The first and second zones are folded along the respective folding guide lines between front and rear halves of the third zone so as to form a pair of tucks which are convex inwardly of the respective leg-holes. Compared to the state before the first and second zones are folded inward, the transverse dimension of the crotch region can be effectively reduced by folding these zones between the front and rear halves of the third zone.
However, the above-cited article has been accompanied with the problem such that the tucks are unfolded along the folding guide lines as the article wearer's legs are guided through the leg-holes of the article and the transverse dimension of the crotch region returns to the dimension before these tucks have been formed. In a consequence, the transverse dimension sometimes becomes larger than the wearer's crotch region and can not be appropriately received in the wearer crotch region. The core becomes more bulky than supposed from its predetermined thickness and stiffness and create a feeling of discomfort against the wearer. In addition, the core laid in the crotch region is irregularly folded or the core is formed with a plurality of irregular wrinkles and deteriorates bodily discharge absorbing function excepted for the crotch region, causing any quantity of bodily discharges to leak sideways from the crotch region.